To characterize the cytochrome b(5) (Cyt b(5))-cytochrome c (Cyt c) interactions during electron transfer, variants of Cyt b(5) have been employed to assess the contributions of electrostatic interactions (substitution of surface charged residues Glu44, Glu48, Glu56, and Asp60 and heme propionate), hydrophobic interactions, and the thermodynamic driving forces (substitutions for hydrophobic residues in heme pocket residues Phe35, Pro40, Val45, Phe58, and Val61). The electrostatic interactions play an important role in maintaining the stability and specificity of the Cyt b(5)-Cyt c complex that is formed. There is no essential effect on the intraprotein complex electron transfer even if most of the involved negatively charged residues on the surface of Cyt b(5) have been removed. The results support a dynamic docking paradigm for Cyt b(5)-Cyt c interactions. The orientation that is optimal for binding may not be optimal form for electron transfer. Substitution of hydrophobic residues does not have a significant effect on the binding between Cyt b(5) and Cyt c; rather, it regulates the electron transfer rates via changes in the driving force. Combining the electron transfer studies of the Cyt b(5)-Cyt c system and the Cyt b(5)-Zn-Cyt c system, we obtain the reorganization energy (0.6 eV) at an ionic strength of 150 mM.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bi036078k | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sequential addition of cations increases photoluminescence quantum yield of metal nanoclusters near unity.
Nat Commun
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, P. R. China.
Photoluminescence is one of the most intriguing properties of metal nanoclusters derived from their molecular-like electronic structure, however, achieving high photoluminescence quantum yield (PLQY) of metal core-dictated fluorescence remains a formidable challenge. Here, we report efficient suppression of the total structural vibrations and rotations, and management of the pathways and rates of the electron transfer dynamics to boost a near-unity absolute PLQY, by decorating progressive addition of cations. Specifically, with the sequential addition of Zn, Ag, and Tb into the 3-mercaptopropionic acids capped Au nanoclusters (NCs), the low-frequency vibration of the metal core progressively decreases from 144.
View Article and Find Full Text PDFAnaerobic sludge digestion enhancement with bioelectrochemical and electrically conductive materials augmentation: a state of the art review.
Chemosphere
January 2025
DICAR University of Pavia, 27100 Pavia, Italy. Electronic address:
Excess biological sludge processing and disposal have a significant impact on the energy balance and economics of wastewater treatment operations, and on receiving environments. Anaerobic digestion is probably the most widespread in-plant sludge processing method globally, since it stabilizes and converts biosolids organic matter into biogas, allowing partial recovery of their embedded chemical energy. A considerable number of studies concerning applicable techniques to improve biogas production, both in quantity and quality, include pre-treatment strategies to promote biosolids disintegration aimed at the release and solubilisation of intracellular energy compounds, inorganic/biological amendments aimed at improving process performance, and sludge thermal pre-treatment.
View Article and Find Full Text PDFCobalt tungstate nanoparticles (CoWO NPs) affect the photosynthetic performance of the green microalga Raphidocelis subcapitata.
Chemosphere
January 2025
Center for the Development of Functional Materials (CDMF), Federal University of São Carlos (UFSCar), Washington Luís Road, Km 235, 13565-905, São Carlos, SP, Brazil.
Innovative applications of cobalt tungstate nanoparticles (CoWO NPs) are directly linked to their increased production and consumption, which can consequently increase their release into aquatic ecosystems and the exposure of organisms. Microalgae are autotrophic organisms that contribute directly to global primary productivity and provide oxygen for maintaining many organisms on Earth. In this paper, we assessed the toxicity of CoWO NPs when in contact with the freshwater microalga Raphidocelis subcapitata (Chlorophyceae).
View Article and Find Full Text PDFThe maize mTERF18 regulates transcriptional termination of the mitochondrial nad6 gene and is essential for kernel development.
J Genet Genomics
January 2025
National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei, Anhui 230036, China. Electronic address:
Mitochondria are semi-autonomous organelle present in eukaryotic cells, containing their own genome and transcriptional machinery. However, their functions are intricately linked to proteins encoded by the nuclear genome. Mitochondrial transcription termination factors (mTERFs) are nucleic acid-binding proteins involved in RNA splicing and transcription termination within plant mitochondria and chloroplasts.
View Article and Find Full Text PDFEnhancing anammox granular sludge for mainstream anammox process by adding iron-loaded diatomite: performance and intrinsic mechanism.
Environ Res
January 2025
School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
Iron-loaded diatomite (Fe-DE) was developed as the innovative material to enhance anammox granular sludge (AnGS) and mainstream anammox performance. By adding Fe-DE with the Fe:DE ratio of 1:20 and the dosage of 3 g/L, the start-up period of mainstream anammox process was shortened from 29 d to 17 d and its nitrogen removal rate was increased from 0.234 kg N/(m·d) to 0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!